chore: Update the `with-supabase` example to use the Supabase Auth block (#78913)
This PR updates the `with-supabase` template to better auth pages,
Tailwind v4 and newest `components.json` for full compatibility with
shadcn/ui.
The `(auth-pages)` folder has been removed. For auth, the template is
now using the [password based auth
block](https://supabase.com/ui/docs/nextjs/password-based-auth) from the
Supabase UI Library which makes it easier to update it and keep it
up-to-date.
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Co-authored-by: Lee Robinson <lee@leerob.com>